When their 23-year-old son died, the lives of David and Vicky Francis crumbled. But a letter he had written in case of such a tragedy has given them a renewed strength. Adam Aspinall reports

"Please do not mourn me for too long. Whatever happened, couldn't have happened any other way...I want you to keep on living life to the full, life goes on," Alex Francis wrote.

It was a heartbreaking letter found among his possessions following the charity worker's death in Africa five months ago.

Those last three words have provided the solace his parents, David and Vicky from Sutton Coldfield, needed and have helped them come to terms with his sudden death.

Alex was in Sierra Leone working for the Canadian charity Right To Play last November when he was taken to hospital after collapsing during a 15km run in aid of HIV/AIDS.

At the time it was suspected he was suffering from Lassa fever, an endemic disease in West Africa and Sierra Leone. He fell into a coma and died ten hours later.

Due to fears of spreading the disease in Europe, Alex had to be buried in an airtight coffin.

More than 400 people flocked to his funeral at Lichfield Cathedral, including a representative of UN High Commission for Refugees.

His father, a consultant neurologist at Queen Elizabeth Hospital in Birmingham, rejected the idea his son died of Lassa fever and has studied medical reports into his death. He believes it was heatstroke not Lassa fever which took his son's life.

He said: "It was a bit of a double whammy for me because I was at the same time a grieving parent and an anguished medic, especially as I did not really know what he had died from.

"At first it was reassuring to hear that they had done everything in their power to deal with an overwhelming infection but when I looked into it more closely it became obvious to me he died from heat stroke.

"But it was my son's decision to go out there and it was my son's decision to run the race.

"There was adequate medical cover but it could perhaps have been more attuned to the risks of heatstroke.

"But Alex accepted the risk and we too accepted the risk on his behalf and after all he was 23-years-old."

Alex had just finished his degree at York in politics, philosophy and economics and while waiting to go out to Sierra Leone had taught basketball in schools around Birmingham.

The former King Edward's School pupil had secured a place at Sandhurst this year.

His mother and father are now raising money for his memorial fund, set up by the charity Right to Play. It has already raised £10,000 for sports infrastructures in Africa.

Mrs Francis said: "I think it's a brilliant idea because it's a sporting commemoration and Alex spent a lot of his time playing and coaching sport.

"We are determined that it funds some infrastructure, one of the ideas is to set-up some kind of basketball court in Sierra Leone which will be a lasting memorial to his name."

Schoolfriend Mark Davis, who took part in the Paris Marathon at the weekend to raise money for the memorial fund, said: "The idea for the run came from a friend of his from university.

"We are aiming to raise about £10,000 and will probably end up getting a little bit more. The very act of taking part in the run is going to be a very important and cathartic process for us."